/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/**
 * @file
 * Dynamic pool memory manager
 *
 * lwIP has dedicated pools for many structures (netconn, protocol control blocks,
 * packet buffers, ...). All these pools are managed here.
 */

#include <netdb.h>

#include "lwip/opt.h"
#include "lwip/debug.h"
#include "lwip/memp.h"
#include "lwip/pbuf.h"
#include "lwip/raw.h"
#include "lwip/udp.h"
#include "lwip/tcp.h"
#include "lwip/priv/tcp_priv.h"
#include "lwip/ip4_frag.h"
#include "lwip/netbuf.h"
#include "lwip/api.h"
#include "lwip/priv/tcpip_priv.h"
#include "lwip/priv/api_msg.h"
#include "lwip/sockets.h"
#include "lwip/netifapi.h"
#include "lwip/igmp.h"
#include "lwip/timeouts.h"
#include "lwip/netif/etharp.h"

/* needed by default MEMP_NUM_SYS_TIMEOUT */
#include "lwip/netif/ppp/ppp_opts.h"
#include "lwip/dns.h"
#include "lwip/priv/nd6_priv.h"
#include "lwip/ip6_frag.h"
#include "lwip/mld6.h"

#define LWIP_MEMPOOL(name, num, size, desc) LWIP_MEMPOOL_DECLARE(name, num, size, desc)
#include "lwip/priv/memp_std.h"

const struct memp_desc *const memp_pools[MEMP_MAX] = {
#define LWIP_MEMPOOL(name, num, size, desc) &memp_ ## name,
#include "lwip/priv/memp_std.h"
};

#ifdef LWIP_HOOK_FILENAME
#include LWIP_HOOK_FILENAME
#endif

#if MEMP_MEM_MALLOC && MEMP_OVERFLOW_CHECK >= 2
#undef MEMP_OVERFLOW_CHECK
/* MEMP_OVERFLOW_CHECK >= 2 does not work with MEMP_MEM_MALLOC, use 1 instead */
#define MEMP_OVERFLOW_CHECK 1
#endif

#if MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC
/**
 * Check that memp-lists don't form a circle, using "Floyd's cycle-finding algorithm".
 */
static int memp_sanity(const struct memp_desc *desc)
{
	struct memp *t, *h;

	t = *desc->tab;
	if (t != NULL) {
		for (h = t->next; (t != NULL) && (h != NULL); t = t->next, h = ((h->next != NULL) ? h->next->next : NULL)) {
			if (t == h) {
				return 0;
			}
		}
	}

	return 1;
}
#endif							/* MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC */

#if MEMP_OVERFLOW_CHECK
/**
 * Check if a memp element was victim of an overflow
 * (e.g. the restricted area after it has been altered)
 *
 * @param p the memp element to check
 * @param desc the pool p comes from
 */
static void memp_overflow_check_element_overflow(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
	u16_t k;
	u8_t *m;
	m = (u8_t *) p + MEMP_SIZE + desc->size;
	for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
		if (m[k] != 0xcd) {
			char errstr[128] = "detected memp overflow in pool ";
			strcat(errstr, desc->desc);
			LWIP_ASSERT(errstr, 0);
		}
	}
#else							/* MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
	LWIP_UNUSED_ARG(p);
	LWIP_UNUSED_ARG(desc);
#endif							/* MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
}

/**
 * Check if a memp element was victim of an underflow
 * (e.g. the restricted area before it has been altered)
 *
 * @param p the memp element to check
 * @param memp_type the pool p comes from
 */
static void memp_overflow_check_element_underflow(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
	u16_t k;
	u8_t *m;
	m = (u8_t *) p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
	for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
		if (m[k] != 0xcd) {
			char errstr[128] = "detected memp underflow in pool ";
			strcat(errstr, desc->desc);
			LWIP_ASSERT(errstr, 0);
		}
	}
#else							/* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 */
	LWIP_UNUSED_ARG(p);
	LWIP_UNUSED_ARG(desc);
#endif							/* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 */
}

/**
 * Initialize the restricted area of on memp element.
 */
static void memp_overflow_init_element(struct memp *p, const struct memp_desc *desc)
{
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0
	u8_t *m;
#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
	m = (u8_t *) p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
	memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
#endif
#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
	m = (u8_t *) p + MEMP_SIZE + desc->size;
	memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
#endif
#else							/* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
	LWIP_UNUSED_ARG(p);
	LWIP_UNUSED_ARG(desc);
#endif							/* MEMP_SANITY_REGION_BEFORE_ALIGNED > 0 || MEMP_SANITY_REGION_AFTER_ALIGNED > 0 */
}

#if MEMP_OVERFLOW_CHECK >= 2
/**
 * Do an overflow check for all elements in every pool.
 *
 * @see memp_overflow_check_element for a description of the check
 */
static void memp_overflow_check_all(void)
{
	u16_t i, j;
	struct memp *p;
	SYS_ARCH_DECL_PROTECT(old_level);
	SYS_ARCH_PROTECT(old_level);

	for (i = 0; i < MEMP_MAX; ++i) {
		p = (struct memp *)LWIP_MEM_ALIGN(memp_pools[i]->base);
		for (j = 0; j < memp_pools[i]->num; ++j) {
			memp_overflow_check_element_overflow(p, memp_pools[i]);
			memp_overflow_check_element_underflow(p, memp_pools[i]);
			p = LWIP_ALIGNMENT_CAST(struct memp *, ((u8_t *) p + MEMP_SIZE + memp_pools[i]->size + MEMP_SANITY_REGION_AFTER_ALIGNED));
		}
	}
	SYS_ARCH_UNPROTECT(old_level);
}
#endif							/* MEMP_OVERFLOW_CHECK >= 2 */
#endif							/* MEMP_OVERFLOW_CHECK */

/**
 * Initialize custom memory pool.
 * Related functions: memp_malloc_pool, memp_free_pool
 *
 * @param desc pool to initialize
 */
void memp_init_pool(const struct memp_desc *desc)
{
#if MEMP_MEM_MALLOC
	LWIP_UNUSED_ARG(desc);
#else
	int i;
	struct memp *memp;

	*desc->tab = NULL;
	memp = (struct memp *)LWIP_MEM_ALIGN(desc->base);
	/* create a linked list of memp elements */
	for (i = 0; i < desc->num; ++i) {
		memp->next = *desc->tab;
		*desc->tab = memp;
#if MEMP_OVERFLOW_CHECK
		memp_overflow_init_element(memp, desc);
#endif							/* MEMP_OVERFLOW_CHECK */
		/* cast through void* to get rid of alignment warnings */
		memp = (struct memp *)(void *)((u8_t *) memp + MEMP_SIZE + desc->size
#if MEMP_OVERFLOW_CHECK
									   + MEMP_SANITY_REGION_AFTER_ALIGNED
#endif
									  );
	}
#if MEMP_STATS
	desc->stats->avail = desc->num;
#endif							/* MEMP_STATS */
#endif							/* !MEMP_MEM_MALLOC */

#if MEMP_STATS && (defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY)
	desc->stats->name = desc->desc;
#endif							/* MEMP_STATS && (defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY) */
}

/**
 * Initializes lwIP built-in pools.
 * Related functions: memp_malloc, memp_free
 *
 * Carves out memp_memory into linked lists for each pool-type.
 */
void memp_init(void)
{
	u16_t i;

	/* for every pool: */
	for (i = 0; i < LWIP_ARRAYSIZE(memp_pools); i++) {
		memp_init_pool(memp_pools[i]);

#if LWIP_STATS && MEMP_STATS
		lwip_stats.memp[i] = memp_pools[i]->stats;
#endif
	}

#if MEMP_OVERFLOW_CHECK >= 2
	/* check everything a first time to see if it worked */
	memp_overflow_check_all();
#endif							/* MEMP_OVERFLOW_CHECK >= 2 */
}

static void *
#if !MEMP_OVERFLOW_CHECK
do_memp_malloc_pool(const struct memp_desc *desc)
#else
do_memp_malloc_pool_fn(const struct memp_desc *desc, const char *file, const int line)
#endif
{
	struct memp *memp;
	SYS_ARCH_DECL_PROTECT(old_level);

#if MEMP_MEM_MALLOC
	memp = (struct memp *)mem_malloc(MEMP_SIZE + MEMP_ALIGN_SIZE(desc->size));
	SYS_ARCH_PROTECT(old_level);
#else							/* MEMP_MEM_MALLOC */
	SYS_ARCH_PROTECT(old_level);

	memp = *desc->tab;
#endif							/* MEMP_MEM_MALLOC */

	if (memp != NULL) {
#if !MEMP_MEM_MALLOC
#if MEMP_OVERFLOW_CHECK == 1
		memp_overflow_check_element_overflow(memp, desc);
		memp_overflow_check_element_underflow(memp, desc);
#endif							/* MEMP_OVERFLOW_CHECK */

		*desc->tab = memp->next;
#if MEMP_OVERFLOW_CHECK
		memp->next = NULL;
#endif							/* MEMP_OVERFLOW_CHECK */
#endif							/* !MEMP_MEM_MALLOC */
#if MEMP_OVERFLOW_CHECK
		memp->file = file;
		memp->line = line;
#if MEMP_MEM_MALLOC
		memp_overflow_init_element(memp, desc);
#endif							/* MEMP_MEM_MALLOC */
#endif							/* MEMP_OVERFLOW_CHECK */
		LWIP_ASSERT("memp_malloc: memp properly aligned", ((mem_ptr_t) memp % MEM_ALIGNMENT) == 0);
#if MEMP_STATS
		desc->stats->used++;
		if (desc->stats->used > desc->stats->max) {
			desc->stats->max = desc->stats->used;
		}
#endif
		SYS_ARCH_UNPROTECT(old_level);
		/* cast through u8_t* to get rid of alignment warnings */
		return ((u8_t *) memp + MEMP_SIZE);
	} else {
		LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", desc->desc));
#if MEMP_STATS
		desc->stats->err++;
#endif
	}

	SYS_ARCH_UNPROTECT(old_level);
	return NULL;
}

/**
 * Get an element from a custom pool.
 *
 * @param desc the pool to get an element from
 *
 * @return a pointer to the allocated memory or a NULL pointer on error
 */
void *
#if !MEMP_OVERFLOW_CHECK
memp_malloc_pool(const struct memp_desc *desc)
#else
memp_malloc_pool_fn(const struct memp_desc *desc, const char *file, const int line)
#endif
{
	LWIP_ASSERT("invalid pool desc", desc != NULL);
	if (desc == NULL) {
		return NULL;
	}
#if !MEMP_OVERFLOW_CHECK
	return do_memp_malloc_pool(desc);
#else
	return do_memp_malloc_pool_fn(desc, file, line);
#endif
}

/**
 * Get an element from a specific pool.
 *
 * @param type the pool to get an element from
 *
 * @return a pointer to the allocated memory or a NULL pointer on error
 */
void *
#if !MEMP_OVERFLOW_CHECK
memp_malloc(memp_t type)
#else
memp_malloc_fn(memp_t type, const char *file, const int line)
#endif
{
	void *memp;
	LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);

#if MEMP_OVERFLOW_CHECK >= 2
	memp_overflow_check_all();
#endif							/* MEMP_OVERFLOW_CHECK >= 2 */

#if !MEMP_OVERFLOW_CHECK
	memp = do_memp_malloc_pool(memp_pools[type]);
#else
	memp = do_memp_malloc_pool_fn(memp_pools[type], file, line);
#endif

	return memp;
}

static void do_memp_free_pool(const struct memp_desc *desc, void *mem)
{
	struct memp *memp;
	SYS_ARCH_DECL_PROTECT(old_level);

	LWIP_ASSERT("memp_free: mem properly aligned", ((mem_ptr_t) mem % MEM_ALIGNMENT) == 0);

	/* cast through void* to get rid of alignment warnings */
	memp = (struct memp *)(void *)((u8_t *) mem - MEMP_SIZE);

	SYS_ARCH_PROTECT(old_level);

#if MEMP_OVERFLOW_CHECK == 1
	memp_overflow_check_element_overflow(memp, desc);
	memp_overflow_check_element_underflow(memp, desc);
#endif							/* MEMP_OVERFLOW_CHECK */

#if MEMP_STATS
	desc->stats->used--;
#endif

#if MEMP_MEM_MALLOC
	LWIP_UNUSED_ARG(desc);
	SYS_ARCH_UNPROTECT(old_level);
	mem_free(memp);
#else							/* MEMP_MEM_MALLOC */
	memp->next = *desc->tab;
	*desc->tab = memp;

#if MEMP_SANITY_CHECK
	LWIP_ASSERT("memp sanity", memp_sanity(desc));
#endif							/* MEMP_SANITY_CHECK */

	SYS_ARCH_UNPROTECT(old_level);
#endif							/* !MEMP_MEM_MALLOC */
}

/**
 * Put a custom pool element back into its pool.
 *
 * @param desc the pool where to put mem
 * @param mem the memp element to free
 */
void memp_free_pool(const struct memp_desc *desc, void *mem)
{
	LWIP_ASSERT("invalid pool desc", desc != NULL);
	if ((desc == NULL) || (mem == NULL)) {
		return;
	}

	do_memp_free_pool(desc, mem);
}

/**
 * Put an element back into its pool.
 *
 * @param type the pool where to put mem
 * @param mem the memp element to free
 */
void memp_free(memp_t type, void *mem)
{
#ifdef LWIP_HOOK_MEMP_AVAILABLE
	struct memp *old_first;
#endif

	LWIP_ERROR("memp_free: type < MEMP_MAX", (type < MEMP_MAX), return;);

	if (mem == NULL) {
		return;
	}
#if MEMP_OVERFLOW_CHECK >= 2
	memp_overflow_check_all();
#endif							/* MEMP_OVERFLOW_CHECK >= 2 */

#ifdef LWIP_HOOK_MEMP_AVAILABLE
	old_first = *memp_pools[type]->tab;
#endif

	do_memp_free_pool(memp_pools[type], mem);

#ifdef LWIP_HOOK_MEMP_AVAILABLE
	if (old_first == NULL) {
		LWIP_HOOK_MEMP_AVAILABLE(type);
	}
#endif
}
